With the development of multimedia technology, digital still cameras, digital video cameras and mobile phones with camera functions have gained increasing popularity among consumers. In addition to their pursuit for the miniaturization of these devices, customers are also demanding for an increasing improvement in the quality (i.e., clarity) of images captured by such devices. On the other hand, whether such devices could capture high quality images heavily depends on the performance of incorporated optics.
In general, a digital camera lens includes at least one diaphragm. FIG. 1 shows a conventional wafer-level optic, which is a diaphragm 1, including: a glass substrate 10 having a first side 101 and a second side 102 opposing the first side 101; a first light-shielding layer 11 on the first side 101, the first light-shielding layer 11 defining a first pattern 111; and a second light-shielding layer 12 on the second side 101. The second light-shielding layer 11 defines a second pattern 121 which is aligned with the first pattern 111, in order to allow passage of light.
However, as conventional techniques generally employ photolithography and etching processes to form the first and second patterns 111, 121 in the light-shielding layers 11, 12, it is difficult to achieve high accuracy in alignment between the ultimately formed patterns. This is detrimental to the optical characteristics of a lens module incorporating the optic, and is thus disadvantageous to the imaging quality of a digital camera in which the lens module is used.